# Magnetic Circuit

An introduction of a magnetic circuit consists of a structure composed for the most part of high permeability magnetic material. The presence of high permeability material causes the magnetic flux to be confined to the path defined by the structure, the current in the electric circuit. The core is assumed to be composed of magnetic material.

Magnetic Circuits In Electrical Engineering :

Practically all electrical power machinery (e.g. transformer, generators, motors) depend for their operation upon the magnetism produced by the magnetic circuits. The closed path followed by magnetic flux is called a magnetic circuit as shown in Fig. Just the closed path followed by the current is called electric circuits. There is a lot of difference between electric and magnetic circuits, discussed in this category of magnetic circuits.

A magnetic circuit consists of a structure composed for the most part of high permeability magnetic material. The presence of high permeability material causes the magnetic flux to be confined to the path defined by the structure, the current in the electric circuit. The core is assumed to be composed of magnetic material, whose permeability is much greater than that of air. The core is of uniform cross-section and excited by a winding having N turns and carrying a current of I amperes. This winding develops flux inside the core. The magnetic flux can be visualized in terms of flux lines.

## Types Of Magnetic Materials

Question formed from this topic like :

Q: Explain the classification of magnetic materials. OR Types of magnetic materials as a magnetic core.

The magnetic materials have some kind of properties known as diamagnetic, paramagnetic or ferromagnetic.

### Paramagnetic Materials

The materials, which are not strongly attracted by a magnet, such as aluminium, tin, platinum, magnesium, manganese etc. are known as paramagnetic materials. The relative permeability is small but positive.

### Diamagnetic Materials

The materials which are repelled by a magnet such as zinc, mercury, lead, sulfur, copper, silver, bismuth, wood, etc., are known as diamagnetic materials. The permeability is slightly less than unity.

### Ferromagnetic Materials

The materials which are strongly attracted by a magnet such as iron, steel, nickel, cobalt, and some of their alloys, areknown as Ferromagnetic materials. The permeability is very high (Varying from several hundred to many thousands).

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